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What Is Surging in a Boiler and Why Is It Dangerous?

One of the most common service calls we get at Calray Boilers is for surging in a boiler. This is a situation that can have long-term negative consequences for your boiler. Fortunately, boiler surging is largely preventable. Here’s how you can tell if your boiler is surging, what causes it, and how to stop it from happening in your New York City building if you are a property owner or manager.

How to Identify Surging in a Boiler

Priming, foaming, churning, and percolating

Boiler surging is sometimes also known as priming or foaming, which hints at what it looks like. When a boiler surges, the water level inside the tank goes up and down violently, like a coffee percolator or the sea during a storm.

As you might imagine, boiler surging is also noisy. The water slapping against the tank gets quite loud, which is often what alerts maintenance to the problem.

All that churning and sloshing also usually shows up in the sight glass. You’ll see the water rising and falling dramatically. The automatic water feeder may be activated more than usual, too, as it “thinks” the water level in the tank is lower than it actually is.

Within the building’s units, surging can result in radiator problems that tenants report, such as:

• Loud banging (water hammer)
• Valves spitting water
• Not enough heat because there’s insufficient steam

Causes of Boiler Surging

Dirty water, poor maintenance, and more

Technically, boiler surging is caused by steam that cannot lift from the water’s surface inside the tank. This is because oil, grease, or particulates (sediment, rust, mineral scale, etc.) have accumulated on the surface. Sometimes grease in the boiler water is a remnant of a newly installed boiler that wasn’t properly cleaned. However, there are other causes of boiler surging as well:

• Oil leaks that infiltrate the boiler water
• Lack of filtration on the water supply
• Low water pH (acidic) due to failure to treat boiler water
• Wrong size burner or burner set too high, causing overfiring
• Problems with a Hartford loop (installed incorrectly or wrong size)
• Piping leading from the boiler is too small, resulting in high steam velocity (Bernouilli’s fluid continuity equation: A1V1 = A2V2, where A is the area of the pipe and V is the velocity of fluid)

It’s not uncommon for boiler surging to be caused by several of the factors above acting on the boiler water simultaneously.

Consequences of Boiler Surging

Flooding and boiler damage

A surging boiler is a disaster waiting to happen in your boiler room, and it can have multiple negative consequences. First, it can cause flooding, which means the water level in the tank becomes too high. This occurs when the automatic boiler feeder keeps getting triggered during troughs in water movement. It sends more and more water to the boiler tank when it’s not really needed.

Flooding puts excessive wear and tear on your boiler and can also result in poor heat produced for building occupants. It can cause sky-high water bills, too, if it goes on too long.

Surging can also result in the boiler firing more often. This uses more gas, which runs up your fuel bill. And like flooding, it causes the boiler to wear faster, thereby shortening its lifespan.

The dirt and debris that cause surging in the first place also reduce the lifespan of a commercial boiler. Therefore, you want to prevent surging before it starts by following the expert tips below.

How to Prevent Surging in a Boiler

Water treatment and maintenance

At Calray Boilers, we take a multifaceted approach when advising our clients on how to prevent boiler surging. Here are the steps you should take to avoid surging and keep your boiler in top shape to extend its lifespan:

1. Always have the boiler cleaned after installation of a new unit or installation of a new tank.
2. Clean the boiler when you notice the water in the sight glass looking dirty (usually it will turn brown or reddish-brown in color).
3. Treat your boiler water to achieve the proper pH. It should be between 7 and 9, so it’s not too basic or too acidic. Calray Boilers can assist you with this, which will protect your boiler tank, improve the boiler’s overall performance, and save on the accumulation of particulate matter in your pipes and radiators.
4. Make sure that if you have a Hartford loop, it’s sized and configured properly.
5. Install the correct size (diameter) piping leading from the boiler to prevent overly high steam velocity as it exits.
6. Schedule professional maintenance on your entire boiler system at least once per year, either at the end of the heat season or in the autumn before the start of cold weather.

Expert boiler service will help catch things that can cause boiler surging, such as burner problems and oil leaks. We also make sure the automatic water feeder and tank sensors are operating correctly. To make this easier for our clients, we offer annual service agreements, which lets you lock in a price and get priority service, with reminders when your maintenance check is coming due.

If your boiler is overdue for a maintenance session, don’t wait until you have a surging problem on your hands before you reach out. Call Calray Boilers today at 212-722-5506 to schedule a checkup.